microscale techniques for the organic laboratory · microscale techniques for the organic...
TRANSCRIPT
Microscale Techniques for the Organic Laboratory
2nd Edition
WEBSITE REFERENCE DISCUSSIONS
Dana W. Mayo
Bowdoin College
Ronald M. Pike
Merrimack College
Peter K. Trumper
University of Southern Maine
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WEBSITE CONTENTS
CHAPTER 3
MICROSCALE LABORATORY EQUIPMENT AND TECHNIQUES
Sand Bath Techniques 8
Metal Heat-Transfer Devices 9
Reflux Apparatus 12
Distillation Apparatus 14
Reduced Pressure Distillation Systems 14
Special Moisture Sensitivity Conditions 16
Collection of Gas Chromatographic Effluents 19
CHAPTER 5
TECHNIQUES 2 AND 3
Simple and Fractional Semimicroscale Distillations
Technique 2: Simple Semimicroscale Distillation. 21
2A. Distillation Theory 21
2B. Steam Distillation 27
Theory 28
Example [2BW]: Illustration of the application of steam distillation
3A. How Spinning Bands Function in Fractional Distillation Columns. 39
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TECHNIQUE 3: Fractional Semimicroscale Distillation
3B. Reduced pressure distillation with microspinning band columns 43
Reduced Distillation Apparatus 43
Example [3BW]: Methylcyclohexane/toluene distillation at 300 Torr
Assembly of the System 45
A standard mixture of 50:50 methylcyclohexane/toluene 46
Vacuum Pumps and Pressure Regulation
TECHNIQUE 5
Crystallization
Two Examples to Practice Recrystallization on a semimicroscale follow:
(This procedure is useful when carrying out scaled-upmicroscale reactions) 61
Example [5AW]: Recrystallization of Benzoin
Example [5BW]: Recrystallization of Naphthalene from a Solvent Pair
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TECHNIQUE 8
Measurement of Specific Rotation
High Performance Polarimeters 64
Optical Rotary Dispersion 65
CHAPTER 6
Spectroscopic Identification of Organic Compounds by Infared Spectroscopy
I. Introduction.
Introduction to Theory 66
A. Molecular Energy 66
B. Molecular Vibrations 67
C. Quantized Vibrational Energy 70
D. Selection Rules 72
1. The Case of HCl 732. The Case of Water 743. The Case of Carbon Dioxide 76
E. Vibrational Coupling 78
1. Coupled Oscillators 782. Second-Order Coupling 79
II. Group Frequencies of the Hydrocarbons
A. Characteristic Group Frequencies of Alkanes 81
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B. Characteristic Group Frequencies of Alkenes 88
1. C=C Stretching 88
2. Alkene C—H 89
3. Out-of-Plane Deformation Modes 91
a. Vinyl Groups 91
b. Vinylidene Groups 91
c. Trans Alkenes 92
d. Cis Alkenes 92
e. Trisubstituted Alkenes 93
f. Tetrasubstituted Alkenes 93
g. Overtones 93
C. Characteristic Group Frequencies of Alkynes 93
1. C≡C Stretching Vibration 93
2. Alkyne C—H Vibrations 94
D. Characteristic Group Frequencies of Arenes 95
1. Group Frequencies of the Phenyl Group 95
a. C—H Stretching Modes 95
b. C=C Stretching Modes 96
c. C—H Bending Vibrations 98
d. Sum Tone Patterns 100
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III. Characteristic Frequencies of HeteroatomFunctional Groups
A. Factors Affecting the Carbonyl Group Frequencies 102
1. Mass Effects 103
2. Geometric Effects 103
3. Electronic Effects (Resonance and Inductive) 104
a. Electronic Effects That Raise the
Carbonyl Frequency 104
b. Electronic Effects That Lower the Carbonyl Frequency 105
c. The Case of Ester Carbonyl Vibrations (CompetingInductive and Resonance Effects) 105
4. Interaction Effects 107
a. Intramolecular Carbonyl Interactions 107
b. Intermolecular Carbonyl Interactions 111
B. Characteristic Frequencies of Functional Groups 112
1. 1-Hexanol 114
2. Hexanal 115
3. 3-Heptanone 117
4. n-Hexyl Acetate 118
5. Hexanoyl Chloride 120
6. Hexanoic Acid 121
7. Hexanoic Anhydride 122
8. Dihexyl Ether 123
9. n-Hexylamine 124
10. Hexanenitrile 126
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11. Hexanamide 127
12. N-Methylhexanamide 128
13. 1-Hexyl Isocyanate 130
14. 1-Hexanethiol 131
15. 1-Chlorohexane 132
16. Chlorobenzene 134
IV. Instrumentation
The Infrared Interferometer 137
WEBSITE DATA FOR CHAPTER 10
Tables of Derivatives
Tables 10.1 – 10.17. pages 143–158